(a) Field of the Invention
The present invention relates to a plasma display panel (PDP), and more particularly, to a terminal area structure of electrodes in a PDP.
(b) Description of the Related Art
A PDP is a display device that uses vacuum ultraviolet rays generated by gas discharge in discharge cells to excite phosphors, thereby realizing the display of images. With its ability to realize high-resolution images, the PDP is emerging as one of the most popular flat panel display configurations used for wall-mounted televisions and other similar large-screen applications. The different types of PDPs include the AC-PDP, DC-PDP, and hybrid PDP. The AC-PDP, utilizing a triode surface discharge structure, is becoming the most common configuration.
In the AC-PDP with a triode surface discharge structure, address electrodes, barrier ribs, and phosphor layers are formed on a rear substrate corresponding to each discharge cell. Sustain electrodes comprised of scanning electrodes and common electrodes are formed on a front substrate. A dielectric layer is formed covering the address electrodes on the rear substrate, and another dielectric layer is formed covering the sustain electrodes on the front substrate. In addition, discharge gas (typically an Ne—Xe compound gas) is filled in the discharge cells.
Using the above structure, an address voltage Va is applied between an address electrode and a scanning electrode to select a discharge cell. If a sustain voltage Vs is applied between the common electrode and the scanning electrode of the selected discharge cell, plasma discharge occurs in the discharge cell. Vacuum ultraviolet rays are emitted from the excited Xe atoms created during plasma discharge. The vacuum ultraviolet rays excite phosphors so that they glow (i.e., emit visible light) and thereby enable the display of predetermined images.
FIG. 10 is a partial enlarged plan view of a conventional PDP, and FIG. 11 is a partial enlarged plan view of electrodes shown in FIG. 10.
With reference to FIG. 10, the PDP structured and operating as described above includes substrates having display region 1 where images are generated, and terminal region 3 formed outside display region 1. One end of electrodes 2 is extended into terminal region 3 for connection to connecting member 5 such as a flexible printed circuit (FPC) or a chip-on-film (COF). Electrodes 2 receive voltages from a drive circuit board (not shown) via connecting member 5. The voltages are used to drive the PDP.
Electrodes 2 have a pitch in display region 1 of the substrate that is different from a pitch in terminal region 3. In particular, electrodes 2 have pitch P1 in effective segments 7 thereof positioned in display region 1, and pitch P2 in terminal segments 9 thereof positioned in terminal region 3. Pitch P2 is smaller than pitch P1. Electrodes 2 make this transition from larger pitch P1 to smaller pitch P2 through intermediate segments 11 thereof. That is, if electrodes 2 are grouped together by a predetermined number of the same (one such group is shown in FIG. 10), intermediate segments 11 of electrodes 2 to the outside of a set number of electrodes 2 positioned in the center of the particular group and which progress linearly to terminal segments 9 are slanted inwardly at predetermined angles toward intermediate segments 11 of these center electrodes 2.
Pitch P2 of terminal segments 9 of electrodes 2 is made small for the following two reasons. First, it is necessary to form an align mark (not shown) in terminal region 3 for better connection of connecting member 5, and space (obtained by smaller pitch P2) is required for the align mark. Further, with use of a plurality of connecting members 5, it is necessary that there be sufficient room between adjacent connecting members 5 to prevent electrical interference between the same.
In the PDP with the above electrode structure, with reference to FIG. 11, if display region 1 is enlarged in an attempt to make better use of the substrates, or if the number of electrodes is increased to realize better picture quality, pitch P3 in intermediate segments 11 is made even smaller at outer electrodes of each grouping of electrodes than pitch P3′ at center areas thereof.
Therefore, when manufacturing the PDP (i.e., during exposure and developing processes for the electrodes), because a distance between intermediate segments 11 or terminal segments 9 is very narrow, it becomes increasingly difficult to design a pattern of terminal segments 9 and of intermediate segments 11 of electrodes 2 that does not have serious flaws. In addition, short circuits may occur in electrodes 2 because of poor shapes of manufactured segments 9, 11.
Hence, the conventional structure places limitations on the degree to which the display region may be increased relative to the terminal region. Stated differently, there are limits to any attempts at making more effective use of the substrate. Furthermore, there are also restrictions with respect to increasing the number of electrodes in an effort to improve picture quality.